1. Field of Invention
The invention relates to an apparatus and process for treating air streams to remove pollutants. More particularly it relates to the use of open weave fiberglass reinforced plastic “FRP” to create a media containment framework within a plenum that contains a remediation media which media facilitates interactions which capture pollutants from an air stream being moved horizontally and radially through the media either inwardly or outwardly.
2. Description of the Relevant Prior Art
Vaporous pollutants, which are frequently toxic or corrosive or both, are created in a multiplicity of municipal, commercial and agricultural processes and become part of output airstreams. Treatment of these output airstreams to strip out the pollutants is important to human health, to prevent damage to equipment, to protect the environment and to provide odor control.
Typical treatment of airstreams is to pass the stream through a reactive media in a containment structure within a plenum which serves as a reactor. Issues include plenum size, choice of material and energy consumption. In instances where the air stream contains corrosive gases, the materials used to form the containment structure are chosen to be as non-reactive as practical. This need has traditionally placed a limitation upon the size of media containment structures. Used alone as inert structural materials, plastics do not have the structural strength for creating large structures. Metals have the strength but corrode too easily.
Over time, two differing reactor designs have emerged. The earlier reactors used vertical flow of the air stream under pressure or vacuum, thus requiring a considerable consumption of energy in their operation.
On the other hand, radial flow reactors work at ambient or just above ambient pressures, requiring no compressors or vacuum units or expensive seals for their operation and presenting less potential for escape of untreated air into the environment.
In general, radial air-flow reactors consist of a containment vessel, a plenum, within which is located a series of baffles that separate the incoming polluted air from the exiting purified air. The space between the baffles holds and supports the remediation media. Commonly, the baffles consist of a pair of cylindrically shaped elements, one having a smaller diameter than the other and being concentrically located within the former. These cylinder walls have pore spaces through which the air passes. In an inward flow reactor, the air stream moves from an inlet manifold through the outer baffle into the remediation medium, and then through the inner baffle and into an exit manifold. Or the reactor can be designed to have a reversed flow direction described as an outward flow reactor.
Past radial flow reactor designs suffered from some problems of their own. One of the main problems being that the structural weakness of non-reactive media containment materials prevented the creation of units large enough to efficiently handle large volumes of pollutants. Increasing the bulk of the solid portion of the containment cylinders to make the walls stronger reduced the amount of open air flow space within the cylinder walls, thus decreasing the efficiency of and increasing the cost of operating the unit.